


The Title Of This Fic Has Been Replaced With “~Chitty Chitty Bang Bang~”

by intothecest



Category: Gravity Falls
Genre: Aged-Up Character(s), Censorship, Double Entendre, F/M, Inappropriate Use of Disney Characters, Incest, It probably should still be rated R though, Non-Explicit Sex, Not Suitable/Safe For Work, Pretty Close to Explicit Though, Seriously this is the smuttiest thing I've written that could technically get a G Rating, Sibling Incest, Twincest, pinecest - Freeform
Language: English
Status: Completed
Published: 2018-06-01
Updated: 2018-06-01
Packaged: 2019-05-16 23:40:33
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,818
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14821110
Author URL: https://archiveofourown.org/users/intothecest/pseuds/intothecest
Summary: Mabel and Dipper return to Gravity Falls, with a difference... they're older, and they're now officially in a secret relationship with each other.  Which means sharing a room could be a lot of fun... but it turns out Gravity Falls has mysteries that keep things G-Rated.





	The Title Of This Fic Has Been Replaced With “~Chitty Chitty Bang Bang~”

The mattress toppled and Dipper slid it in place over the other one, then stood up and wiped his slick, sweaty forehead with the back of his hand. 

That was a lot more work than it should have been, getting the room ready for another summer at the Mystery Shack. First he had to clear out all the crap his great uncle stored in the room during the rest of the year, while he and his twin sister weren’t visiting. That included the dangerous or dubious merchandise Grunkle Stan was slowly been auctioning off online as collectables (like the faerie-finder hats that had magnifying glasses on them and had regularly caught fire on warm summer days), back stock of items that he had high hopes for but only sold a few a year (like the _Croonicorn_ , a horned horse in a suit that sang and danced along to Rat Pack songs), the failed exhibits nobody wanted to see (like the large plastic crescents that were supposed to be Paul Bunyan’s toenail clippings), and worst of all, the boxes of Stan’s self-published book _“Natural Constipation Cures They Don’t Want You To Know About,”_ featuring a picture of Grunkle Stan’s face with an expression that would haunt Dipper’s nightmares for years. Those boxes were a particularly heavy load he did not like carrying around, and it was a lot of work to get them out. Next, after the room was empty, then he had to sweep, and finally, he had to drag the spare mattresses from downstairs. Exhausting, especially doing it all by himself. 

If Dipper wanted to avoid all that unnecessary work, the logical thing to do would be to wait until everyone got back and ask Soos for help, but there was a method to his madness. If he did it alone, nobody would have the chance to suggest that, this year, maybe they should just convert Soos’ break room into another bedroom, that maybe, at the twins’ age, it was inappropriate for two opposite sex siblings to be sharing a room.

But if the room was already set up, he could pretend that he just didn’t consider any other options and just did what they’d always done before… and now, after all that work, he could complain he was too tired to drag the mattress back downstairs. And what would it hurt if they shared a room?

The only one who’s opinion mattered to him was Mabel, and he knew his sister wouldn’t have a problem with it, at least not now that they’d become far closer than twins should probably be… but they were looking forward to being even closer. That was part of the excitement of returning to Gravity Falls this year… it was so hard to get real alone time at home. But here, there was just occasionally Soos and Wendy during the days, and during the nights, only Grunkle Stan, who was starting to go deaf, and, especially with his hearing aid out, slept like the dead. In fact, the last time the Mystery Shack got destroyed (as part of a spectacular final adventure the night before they had to catch the bus back home), Stan slept right through the whole thing! And there was a giant roaring monster involved… surely if he didn’t hear that, he’d never hear a few squeaky bedsprings, if Dipper got really lucky.

That potential wasn’t the only reason, either. He liked sleeping in the same room as his sister, even last year, when they were JUST siblings, not in a for-real relationship with kissing and touching and more. There was something about sleeping next to somebody, who’d be there, even if you couldn’t see them in the dark… if you had a nightmare, they’d gently shake you awake before it got too bad, and if a real monster snuck in through the window in the middle of the night and say, sat on your chest, and tried to suck out your soul, or tried to eat all your hair, they’d be right there to help you fight it off. That wasn’t just hypothetical… each of those situations had actually happened. One night Dipper woke gasping for breath while Mabel beat a little troll-like thing with a golf club, and another time, he turned over in bed, opened his eyes, and he watched a creature that looked like a bat in a bib cutting up and eating his sister’s long brown tresses like they were spaghetti. Literally, he was twirling them around a fork and cutting before shoving it in its mouth. If Dipper hadn’t been there, she would have woken up bald like Pacifica, Wendy, Robbie, and a handful of other townspeople. But because he was there and heard a chewing noise, he was able to solve the mystery. He woke his sister immediately with a yell that was only a little like a high-pitched shriek, and the two of them trapped the creature in an old shirt and forced it to confess that the new shampoo brand they were all using was irresistible to his species. Once they discovered that (and after one emergency hair cut to fix Mabel’s lopsidedness that wound up making his sister look ravishing… not bad for Dipper’s debut effort as a hair stylist), it was easy to put an end to the baldness scourge. They were heroes, at least for a few days. 

So Dipper was well familiar with the kind of dangers you risk, and opportunities you miss, when you sleep alone, but even those weren’t the main reason he liked sharing a room with Mabel. Because, even if there’s nothing going on, you can just wake in the middle of the night and know… you’re not alone. That’s powerful. 

But of course, it was hard to deny that when you’re sleeping in the same room with your girlfriend… well, that just makes everything better. Late night snuggles, a warm body to fend off against the sometimes surprisingly chilly Oregon summer nights and the potential for wandering hands and more.

A river of sweat tickled its way down from his hair and right into his eye, making him wince at the stinging sensation. He wiped himself again, this time with his shirt, and then sniffed his armpits. Phew, there’d be low chance of snuggling, and less chance of more, if he continued to smell like this. Time for a shower.

—-=-=—-

Ten minutes later, Dipper emerged from the bathroom, a towel wrapped around his waist, and still softly singing along with the last song that he’d had playing on shuffle, BABBA’s catchy but somewhat perplexing and ill-conceived hit "Alamo."

When he entered the room, a warm hand grabbed his and pulled him along, joining the song in a high-pitched cheerful voice with an adorable little uneven waver to it. “ _Al-a-mo! My heart’s under siege and you won’t let it go!_ ”

Dipper grinned at his sister, allowing her to pull him into the room, although he had to keep one hand firmly on the knot in his towel to ensure it wouldn’t fall off. He gave the next line as she waggled her shoulders back and forth in front of him. “ _Al-a-mo! I’m begging for mercy I hope you don’t show!_ ”

Together, they sang the final line. “ _Al-a-mo! I’ll always remember how you laid me low…_ ” and ended it with Dipper spinning his sister like they were ballroom dancing, and the two grinning at each other madly.

“When did you get back?” he asked.

“A couple minutes ago. While you were in the shower… I was going to come in and say hello, but it sounded like you were finishing up." She turned in a slow circle, taking in the room for his benefit, even though she’d surely seen when she first entered before he got out of the bathroom. "Wow, it looks almost just like we left it. This must have been a lot of work.”

She might not have known exactly how much work it was, but she had an idea. On the ride from the bus station, Stan had said that attic was full of old junk. Then they split up, as Stan had to help Soos with a minor legal matter, and Mabel wanted to see some friends. That gave Dipper the alone-time he needed to get the job done. “It wasn’t so bad,” he said, and then listed the steps so she knew exactly how bad it was while pretending it was no big deal because it was for her. Which was true, in its way. 

“You should have waited for me to help… or at least for Soos.”

He shrugged, a little self-conscious. “It’s fine, Mabel, really, I was home, and I wanted to get it done before Stan and Soos got back and said they had other plans." Her eyes twinkled and brows raised, and Dipper knew she realized exactly why he’d done it… to make sure they could share a room. And she was indeed pleased, which was a relief… he had worried that maybe she actually did want her space. 

But she hugged him, then after letting go, said, "I still should have helped. It’s just, it’s been, like, forever since I’ve seen Candy and Grenda, and they’d never forgive me if I didn’t stop by them first.”

“How are they?”

“Good. Grenda’s part of a band now, I told her we’ll go to see her play this Friday. And Candy’s, she’s got a summer job this year at the Arcade, so… you know, free tokens. I can hook you up." She nudged him with an elbow.

He smiled, even though she nudged a little too hard and it actually hurt. He didn’t want to look like a wuss, so he took it without even making a grimace. "Sweet.”

Suddenly remembering a piece of good gossip, Mabel’s face lit up. “And she’s seeing somebody!”

Dipper was going to say, “Great,” but before he did, he had to stop and ask. “… Somebody human?" This was Gravity Falls. Heck, she worked at the Arcade, so she could even be dating Rumble McSkirmish. 

"I think so,” Mabel said. “It’s slightly possible that he’s a _banhee_.”

“ _Banhee_?”

“A male _banshee_. I only talked to him on the phone, but… he sure screams a lot . I mean, they’re good screams, like, when he gets really excited about something, like talking to his girlfriend’s friend, so, he seems nice." Candy was always so quiet and shy, it was hard to picture her with a guy who was really loud, but then sometimes opposites attract. 

"As long as she’s happy, I guess… and he doesn’t try to eat her.”

Mabel’s eyelids narrowed in a sultry way, and she said, “ ** _~Like the Crocodile in Peter Pan.~_** ” What was weird was that there was nothing unusual about what she said... well, the reference did come a bit out of nowhere, but non-sequiturs weren't that strange for Mabel. But it was weird because nothing in what she said, or even the intonation she said it with justified that sultry look she gave along with it, and, weirder still, her lips didn’t seem to move in time with the words. It was like somebody had dubbed over her. “Something wrong?”

He realized his confusion must have shown on his face. And he wasn’t even sure there was anything to be confused about. “No, I think I’m just tired.”

“I bet, doing all this work here by yourself. Now I’m glad I got you a gift.”

He wasn’t expecting that. “A gift?" Something from the claw machine at Candy’s arcade maybe? Mabel went to her bed where she left her purse, and then pulled out a a flat piece of wood and handed it over. "You didn’t have to get me a gift…”

“I didn’t have to, but I wanted to. Besides, it’s more for the room than you.”

“What is it?” he asked. It looked like a ordinary board of wood, but then he turned it over. On it was a woodcarving of a sailing ship, one of those old ones with the multiple sails. Very much like…

She finished the thought, like she often did. “It’s like the painting you used to have in our room!" It got destroyed when they used it as a shield against a fire-breathing monster. "You know, the galleon.”

“Frigate,” he said automatically. Neither of them figured out exactly what class of ship it was, Wikipedia was surprisingly unhelpful on the subject, but whenever they argued on the subject, they had a pattern.

“Don’t get angry, Dipper,” she said, completing the joke. “Just enjoy the gift. Anyway, it does look awfully similar to the painting, don’t you think?”

“You’re right… I think it’s even the same artist." There was a tiny signature in the corner that looked like "BS&P,” a signature he remembered from the painting that hung around his bed. “Where’d this come from?”

“Apparently they’re everywhere in Gravity Falls. That’s what Grenda says, anyway.” That twigged on some faint memory of Dipper’s, like maybe he’d read something about it long ago, but had forgotten. “This one was actually Candy’s, but she had to take it off her wall to put in a new bookshelf, and she said she really didn’t want it anymore, now that she has a boyfriend. Anyway, I remembered you always liked that old painting, and it’s gone, so…" 

He looked down at the board in his hands, touched. "Thanks, Mabel." The bare spot on the wall where there once was a painting did need a little something, although this something seemed a little too little. Still, he didn’t have any better options. "So, I guess I should nail this up here?”

Mabel bit her lip. “If that’s the nailing you’re really interested in doing right now, but you know… Stan’s probably not going to be home for a few hours.”

“For a parking ticket? That shouldn’t take that long, it’s not like the court here’s very busy. In fact, they should be home by now, shouldn’t they?”

“They should,” Mabel agreed. “Except I got a call from Soos while you were in the shower. Apparently _somebody_ called the judge a shiny-headed moron, and so the judge threw Grunkle Stan into jail until he apologizes.”

Dipper considered this, and what he knew about Stan, and said, “So, we’ve got about three hours?”

Before he even finished, Mabel agreed, her words running over his. “About three hours, yeah." 

"Two adventurous siblings can do a lot in three hours left unsupervised. Do you have any ideas?" 

Mabel rocked back and forth on her feet, standing first on her toes, then on her heels, then back again. "Well, first, I really would like **_~to watch Disney XD.~_** ”

Okay, that wasn’t what he expected. It was so much not what he expected that he had to check to make sure he hadn’t heard wrong. “… did you just say ‘watch Disney XD?’" Maybe she was teasing him.

She looked a little confused too, her eyes squinting and one eyebrow raised. ”… I guess.“

"So… there’s something good on?”

“No… I really don’t want to do that. I don’t know why I said that. What I meant to say is, if you wanted to, you can **_~watch a Phineas and Ferb marathon his afternoon.~_** " She looked around, eyes narrowed like the universe had just offended her somehow. "What the **_~Fish Hooks?~_** Why am I saying all this weird **_~Stitch!~_** " 

"You mean you’re not doing it on purpose?" Dipper realized that her lips weren’t moving in time to her words all the time, whenever she mentioned a Disney character, like earlier, she seemed like she had been badly dubbed.

She shook her head. "Maybe you should tell ME what you want to do?”

“Well, I’d never say no to a little french **_~Kid vs. Kat episode~_** with my sister. Wow, that is weird.”

“You can’t use… salty language either?”

“It wasn’t even salty! What’s happening?”

Mabel thought for a moment and said, “Well, experience tells us that when something strange happens, it’s always the newest element to come into our lives." 

"That’s true, but we just back into town, so it could be anything…" He looked down at the board still in his hands. This was, _literally_ , the newest thing. And he thought he remembered _SOMETHING_ about magical pieces of hidden art from when he still had the journal. Yes, now that he wracked his brain, there was something else, too… not a reference to this specific thing, but in the journal somebody wrote that he couldn’t write his true feelings because of the influence of the ship… ship of the something… something starting with C. His eyes widened. "I think… I think this is magic, and it’s preventing us from saying certain things that it doesn’t approve of.”

“How do you figure that, Dip?”

He held up the ship-side towards his sister, pointed at it. “See this ship here? I think it’s supposed to be a censor ship.” He never really put it together then, because it never meant anything to him. Maybe the painting had the same effect, but he might never know… it’s not like he ever tried to swear or do anything bad.

“Wait,” Mabel said. “You’re saying we’re under the influence of the censor ship board?" He shrugged, aware of how ridiculous it sounded, but unable to do anything about it. "Isn’t that a little on-the-nose as far as magical-Gravity-Falls-stuff goes?”

“It’s not as bad as the Manotaurs,” he pointed out.

“Touché. So does that mean we have to be G-rated the whole summer?”

He hoped not, especially because he was pretty sure that some things that were G-rated if he did them with a random girl were suddenly not G-rated if they were done with Mabel. After all, he couldn’t even say the k-word in connection to her. “I don’t know. Maybe we just have to be away from the board.”

Mabel eyed him, and her gaze finally centered on his towel, still the only thing he was wearing. “Let me try something." Before he could reach, her hand whipped out, grabbed the towel, and pulled.

Suddenly, they were enveloped in blackness. All they could see, it seemed, were each other’s eyes, except when they blinked, and then it would be totally dark.

"Wow, that was kind of an over-reaction,” Mabel said. “I thought it was just going to blur you.”

“I guess turning out the lights was easier." So far, the board had always censored something with something plausible… sudden darkness was plausible, a weird blur, not so much. As he thought about this, Dipper noticed his sister’s eyes drop down again, even though she couldn’t possibly see anything, and then… "Mabel, what are you doing?”

“What does it feel like I’m doing?”

“Like you’re… actually, I don’t think I can say right now.”

“So I guess we can still do stuff, we just have to do it in the dark and be very ambiguous.”

“I guess that makes sense,” Dipper said. “Otherwise I don’t think Gravity Falls would have much of a population left if people couldn’t **_~stream Doc McStuffins from the Disney website~_** once in a while. Uh… not that I’m complaining, but maybe we should just get rid of the board and see what happens?”

“Oh, come on, Dipper, it’ll be fun. Hey, remember when we had that power failure during that storm and Mom and Dad weren’t home?”

He thought back fondly on that night, and even more fondly as, in the artificial dark imposed by the censor ship board, he felt things which could not be described without using the name of some cartoon character, although that might not be so bad (as long as the board didn’t make him shout out Wendy Darling at an inopportune moment). He was surprisingly up for some ambiguous fun in the dark…

—-=-=—-

“See, what did I tell you, Soos?” Grunkle Stan said, loosening his tie as he came in the door. “I got you out of your parking ticket, _and_ , most importantly, I didn’t have to apologize to that stupid judge. That’s a life lesson for you, kid, when all else fails, bribe the court clerk!" He laughed his short old-man laugh. 

Soos followed him into the Shack. "Gee, thanks, Mister Pines, that really means a lot… you really didn’t have to spend two hundred on a bribe for a fifty dollar ticket.”

“It was my pleasure. And don’t worry, just so you’re not put out all at once, I’ll only take fifty out of your next six paychecks." Soos’ normally cheery face fell at that, but only for a moment. Life was too good to sweat the small stuff. And Grunkle Stan’s memory wasn’t the best anymore, he’d probably forget anyway. "Now, where do you think the kids are?”

Soos could hear it since they came in, a rhythmic thumping and squeaky bedsheets, along with some breathless shouts. "I, uh, think they’re upstairs. Fighting, I think.“ Or hoped.

Grunkle Stan clapped his hands to his head and tilted it towards the ceiling. "Fighting? Why the heck are they fighting?" He stuck one finger in his ear, adjusted the hearing aid.

He probably didn’t have to, since they seemed to be getting louder. "Oh, Mabel…” Dipper cried. “Your **_~Pumba~_** is so good, but I think I’m going **_~Goofy~_** … man, I can’t take it much longer!”

“Hold on one second, Dipper! **_~Pocahontas!~_** That’s right, **_~Pocahontas!~_** Oh! Oh! **_~Aurora! AURORA! AURORRRRAAAAAA!~_** ”

“Yes! Yes! That’s it! Oh, **_~Tinkerbell~!_** ” 

Soos and Stan looked at each other for about ten seconds that seemed to stretch out for eternity, and then Stan broke into a grin. “See, just when you think they’re all grown up, you catch them still arguing over their favorite Disney characters." He winked. 

Soos’s eyes stayed wide open, like he’d seen something that could never be unseen, when in actual fact he’d seen nothing at all but mental pictures informed by his own experiences shouting out the names of cartoon characters when he meant other things. Those were enough. After a few seconds, he said, in a monotone, "Yes, that must be it.”

Mabel’s voice seemed a little less energetic than usual, like she’d just done some strenuous exercise, but it was still pretty loud. “Hey, Dipper, the lights are back! We must have totally burnt it out or something!”

Soos couldn’t hear Dipper’s reply, and he was pretty sure Stan didn’t even hear what Mabel had said, or he probably wouldn’t have said what he did next, “Let me just go run up and grab them and we’ll all go to Greasy’s for dinner.”

Before Stan could get more than a step up the stairs, Soos laid a meaty hand on his shoulder. “You know what, let’s just give them a few minutes.”

“What? Why?”

“Just… just, trust me, dood.”

**THE END**

**Author's Note:**

> For the record, this was originally written before the Stanford Pines reveal, as such, Grunkle Stan is the only Stan in evidence and various things implied by the finale did not come to pass.


End file.
